Understanding the enhanced catalytic activity of high entropy alloys: from theory to experiment

Abstract

High-entropy alloys (HEAs) have evolved to be one of the most popular materials in the last decade. Their unique configuration and attractive properties make HEAs one of the most promising...

FeCoNiMnCr High-Entropy Alloy Nanoparticle-Grafted NCNTs with Promising Performance in the Ohmic Polarization Region of Fuel Cells

“…17,19 In HEAs, the sufficiently high thermal energy of a multimetal solid solution ensures that each constituent element occupies a random position in the final crystal structure. 12 Unlike traditional alloys, HEA assimilates four core intrinsic effects, namely, (i) high-entropy effect (promotion of mutual solubility), (ii) cocktail effect (multielemental character at the atomic level, which is expected to offer a variety of active sites and thus the continuous distribution of adsorption energies), (iii) sluggish diffusion (suppression of intermetallic-phase segregation, which further imparts excellent structural thermal/chemical stability), and (iv) lattice distortion (atomic size mismatch causes severe lattice strain that shifts the overall d-band center of the alloy and thus has potential to modify the physicochemical properties). 12,13,17 Inspired by these material features, HEAs have been envisioned as a promising solution to many problems, especially in catalysis where efficacy and stability are much-needed traits.…”

“…12 Unlike traditional alloys, HEA assimilates four core intrinsic effects, namely, (i) high-entropy effect (promotion of mutual solubility), (ii) cocktail effect (multielemental character at the atomic level, which is expected to offer a variety of active sites and thus the continuous distribution of adsorption energies), (iii) sluggish diffusion (suppression of intermetallic-phase segregation, which further imparts excellent structural thermal/chemical stability), and (iv) lattice distortion (atomic size mismatch causes severe lattice strain that shifts the overall d-band center of the alloy and thus has potential to modify the physicochemical properties). 12,13,17 Inspired by these material features, HEAs have been envisioned as a promising solution to many problems, especially in catalysis where efficacy and stability are much-needed traits. 12,14 However, a facile and user-friendly design for the development of nanostructured HEAs is the foundation for their swift and favorable adoption in heterogeneous catalysis, energy storage, and environmental redemption, though a challenging task to accomplish.…”

“…12,13,17 Inspired by these material features, HEAs have been envisioned as a promising solution to many problems, especially in catalysis where efficacy and stability are much-needed traits. 12,14 However, a facile and user-friendly design for the development of nanostructured HEAs is the foundation for their swift and favorable adoption in heterogeneous catalysis, energy storage, and environmental redemption, though a challenging task to accomplish. 12,17 The research focusing on HEA-based electrocatalysts is still in its infancy, and one of the immediate limitations in this regard is their complex/sophisticated and energy-and time-consuming synthesis methodologies (such as the carbothermal-shock method, extended mechanical ball milling, liquid metal dealloying, pulse laser ablation, fast-moving bed paralysis, etc.).…”

“…12,14 However, a facile and user-friendly design for the development of nanostructured HEAs is the foundation for their swift and favorable adoption in heterogeneous catalysis, energy storage, and environmental redemption, though a challenging task to accomplish. 12,17 The research focusing on HEA-based electrocatalysts is still in its infancy, and one of the immediate limitations in this regard is their complex/sophisticated and energy-and time-consuming synthesis methodologies (such as the carbothermal-shock method, extended mechanical ball milling, liquid metal dealloying, pulse laser ablation, fast-moving bed paralysis, etc.). 2,10−17 It is the need of the hour to develop a userfriendly, facile methodology capable of possible scaling opportunities to widen the horizon and adaptability of HEA in a heterogeneous catalysis community to explore and understand the hidden potentials and insights toward water/ oxygen electrochemistry, in particular.…”

As-cast microstructure and properties of non-equal atomic ratio TiZrTaNbSn high-entropy alloys

“…However, the Al, Co and Ni elements are cytotoxic and may induce apoptosis. Todai et al [9,10] prepared a series of titanium high entropy alloys (TiZrNbTaMo, TiZrNbTaHf) for bone repair using alloying elements without cytotoxicity to humans, and their mechanical properties and biocompatibility are better than 316SS alloy and pure Ti alloy. Yuan et al [11,12] designed and prepared 26 kinds of Ta x Nb x HfZrTi high entropy alloys, which showed that the elastic modulus of high entropy alloy with BCC structure is low and suitable for implantation materials.…”